import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.lang.reflect.Method;

class HelloWorld 
{
	public static void main(String[] args) throws Exception 
	{
		System.out.println("Hello World!");

		//HelloWorld hello = new HelloWorld();
		
		String input = new BufferedReader(new InputStreamReader(System.in)).readLine();
		
		System.out.println("input : " + input);
		//hello.gugudan3();
		//hello.star1();
		//hello.star2();
		//hello.star3();
		//hello.starLine();
		//hello.starLine2();
		
		//Expression ex = new Expression(hello, input, new Object[]{});
		//ex.execute();
		
		Object obj = Class.forName(HelloWorld.class.getName()).newInstance();
		Method method = obj.getClass().getMethod(input, new Class[]{});
		method.invoke(obj, new Object[]{});
		
		
	}

	public void gugudan(){
		for(int i=2; i< 10; i++){
			for(int j=1; j<10; j++){
				System.out.println(i + " * " + j + " = " + (i * j));
				
			}
		}
	}

	private void gugudan2(){
		for(int i=9; i> 1; i--){
			for(int j=1; j<10; j++){
				System.out.println(i + " * " + j + " = " + (i * j));
			}
		}
	}

	private void gugudan3(){
		for(int i=2; i< 10; i++){
			if( i % 3 == 0 ){
				for(int j=1; j<10; j++){
					System.out.println(i + " * " + j + " = " + (i * j));
				}
				System.out.println();
			}
		}
	}

	private void star1(){
		for(int i=1; i< 6; i++){
			for(int j=0; j<i; j++){
				System.out.print("*");
			}
			System.out.println("");
		}
	}

	private void star2(){
		for(int i=6; i > 0; i--){
			for(int j=0; j<i; j++){
				System.out.print("*");
			}
			System.out.println("");
		}
	}

	private void star3(){
		for(int i=1; i<6; i++){
			for(int j=5; j>i; j--){
				System.out.print(" ");
			}
			for(int k=1; k<i*2; k++){
				System.out.print("*");
			}
			System.out.println("");
		}

		for(int i=1; i<6; i++){
			for(int j=1; j<i; j++){
				System.out.print(" ");
			}
			int z = (i * 2);
			for(int k=11; k>z ; k--){
				System.out.print("*");
			}
			System.out.println("");
		}
		
	}

	private void starLine(){
		int row = 10;
		int idx = row - 1;
		for(int i=1; i<row; i++){
			for(int j=idx; j>i; j--){
				System.out.print(" ");
			}
			int z = i * 2;
			for(int k=1; k<z; k++){
				if(k == 1 || k == (z - 1) || i == idx){
					System.out.print("*");
				}else{
					System.out.print(" ");
				}
			}
			System.out.println("");
		}
	}

	private void starLine2(){
		int row = 10;
		int idx = row - 1;
		for(int i=1; i<row; i++){
			for(int j=idx; j>i; j--){
				System.out.print(" ");
			}
			int z = i * 2;
			for(int k=1; k<z; k++){
				if(k == 1 || k == (z - 1)){
					System.out.print("*");
				}else{
					System.out.print(" ");
				}
			}
			System.out.println("");
		}
		idx = idx * 2 + 1;
		for(int i=1; i<row; i++){
			for(int j=1; j<i; j++){
				System.out.print(" ");
			}
			int z = i * 2;
			for(int k=idx; k>z ; k--){
				if(k == idx || k == (z + 1) ){
					System.out.print("*");
				}else{
					System.out.print(" ");
				}
			}
			System.out.println("");
		}
	}
}
